<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        *{margin: 0; padding: 0;}
        #btn{
            width: 150px;
            height: 35px;
            border: 1px solid #ccc;
            background: purple;
            display: block;
            margin: auto;
            color: #fff;
            cursor: pointer;
        }
        .menu{
            width: 148px;
            border: 1px solid #ccc;
            margin: auto;
            border-top: none;
            display: none;
            overflow: hidden;
        }
        .menu ul{
            list-style-type: none;
        }
        .menu ul li{
            height: 30px;
            line-height: 30px;
            text-align: center;
        }
    </style>
</head>
<body>
<div class="menu">
    <ul>
        <li>德玛夏亚</li>
        <li>德玛夏亚</li>
        <li>德玛夏亚</li>
        <li>德玛夏亚</li>
    </ul>
</div>
<input type="button" value="向下滑动" id="btn">

</body>
</html>
<script src="js/jquery-1.10.1.js"></script>
<script>
    $(function () {
        $("#btn").click(function () {
            $(".menu").stop().slideToggle();
        })
    })
</script>